1. Field of the Invention
The present invention relates to a recording and reproducing system for recording and reproducing image information onto and from a recording medium such as a DVD or the like, and relates, more particularly, to a recording and reproducing system equipped with a copy protection function of restricting copying of image information such as picture or the like and a recording apparatus and a reproducing apparatus suitable for use in this recording and reproducing system.
2. Description of the Related Art
A DVD is a recording medium having a large recording capacity, and can record, for example, digital video information equivalent to one volume of moving picture film. Because of this large capacity, a DVD has come to be distributed as an image recording medium for replacing a video cassette of VHS system. A DVD exists in two types; a DVD onto which a recording or a rewriting cannot be done (It is referred to as a xe2x80x9cread-only DVDxe2x80x9d, hereinafter.), and a DVD onto which a recording or a rewriting can be done (It is referred to as a xe2x80x9crecordable DVDxe2x80x9d, hereinafter.). When a recordable DVD is used, it is possible to digitally copy the whole content of a moving picture recorded on the DVD.
Along with the distribution of the recordable DVD, there has been developed a system for digitally transmitting a moving picture or the like from a broadcasting station to general subscribers. When this system has been achieved, it becomes possible for subscribers to not only enjoy watching a high-definition moving picture at home but also digitally record the moving picture transmitted from the broadcasting station onto a DVD and prepare a replica disk in an easy manner.
On the other hand, the act of copying a moving picture or the like without permission is restricted by the copyright law, etc. Particularly, when a moving picture or the like is copied digitally, there occurs no quality degradation in the moving picture copied. Accordingly, it is necessary to severely restrict the copying of digital video information using a DVD in order to promote the distribution of DVD as well.
In order to restrict the recording or copying of digital video information, various methods have been proposed. For example, there is proposed a method of embedding identification information for restricting the copying into digital video information at the time of recording the digital video information onto a DVD. Such a system is generally called a CGMS (Copy Generation Management System). This identification information represents one of the following: (1) prohibiting the copying (hereinafter to be referred to as xe2x80x9cNever Copyxe2x80x9d), (2) permitting the copying only once (hereinafter to be referred to as xe2x80x9cOne Copyxe2x80x9d), and (3) permitting the copying without restriction (hereinafter to be referred to as xe2x80x9cCopy Freexe2x80x9d). When digital video information embedded with this kind of identification information is copied onto other DVD, a recording apparatus reads out the identification information from within the digital video information, and if this identification information shows Never Copy, the recording apparatus does not record this digital video information.
Further, there is also proposed a method of restricting the copying of a picture or a video image by embedding identification information having a function similar to the above into the display range of the image or the video image as a watermark.
Further, a method of scrambling a picture or a video image at the time of recording or reproducing this image or video image also contributes to restricting the recording or reproducing digital video information.
In order to restrict the copying of digital video information by using the above-described identification information, it is necessary to prepare a recording apparatus or a reproducing apparatus equipped with a function of recognizing the identification information based on a predetermined rule prescribing a disposition of the identification information, a decision method, etc. (hereinafter to be referred to as a compliant recording apparatus and a compliant reproducing apparatus respectively).
When other recording apparatus or reproducing apparatus not equipped with the function of recognizing the identification information (hereinafter to be referred to as a non-compliant recording apparatus and a non-compliant reproducing apparatus respectively) is used, there is a case where the identification information is disregarded and digital video information is copied although the information is Never Copy digital video information. If the compliant reproducing apparatus has allowed a reproduction of digital video information copied by the non-compliant recording apparatus, the copying of the Never Copy digital video information is implicitly permitted. In other words, a person who has copied the Never Copy digital video information by the non-compliant recording apparatus is not punished and does not feel any inconvenience at all despite the fact that he or she has copied the Never Copy digital video information. If this situation is left untouched, it is not possible to promote the distribution of the compliant recording apparatus and compliant reproducing apparatus, and has a problem that it is not possible to restrict the copying of digital video information.
Further, in the case of One Copy digital video information, this information can be recorded only once by a compliant recording apparatus. When digital video information recorded by this compliant recording apparatus is reproduced by a non-compliant reproducing apparatus, unlimited copying of the digital video information is allowed based on this non-compliant reproducing apparatus.
Further, in general, a reproducing apparatus can convert digital video information recorded on a DVD into analog information and outputs the information to the outside. Some recording apparatuses can convert analog video information such as a picture or a video image into digital information and record it in a DVD. Accordingly, in order to effectively restrict the copying of digital video information, it is not sufficient to restrict only the copying of digital video information achieved by digitally transmitting the digital video information from a reproducing apparatus to a recording apparatus, that is, the copying by digital transmission. In other words, it is also necessary to restrict the copying of digital video information achieved by converting the digital video information into analog video information by a reproducing apparatus and sending this analog video information to a recording apparatus by analog transmission, that is, the copying by analog transmission.
It is therefore an object of the invention to provide a recording/reproducing system, a recording apparatus and a reproducing apparatus which can reduce unlimited copying of recorded/reproduced information carried out by other recording apparatus or reproducing apparatus not equipped with a function of restricting the copy of recorded/reproduced information, and which can effectively restrict the copying of recorded/reproduced information.
The system in accordance with the present invention comprises a recording apparatus for recording record information onto a recording medium as digital data and a reproducing apparatus for reading the record information from the recording medium and outputting the read record information in order to reproduce the record information recorded on the recording medium.
The record information includes: image information which represents an image or a picture; a first identification information which represents any one of never copy, one copy and copy free; and a second identification information which represents any one of at least the never copy and the one copy.
The never copy indicates that copying of the information is prohibited. The one copy indicates that the copying of the information is permitted only once. The copy free indicates that the copying of the information is permitted.
The recording apparatus comprises: an input device for inputting the record information; a first recording determination device for determining whether the first identification information included in the input record information indicates the never copy, the one copy or the copy free; a second recording determination device for determining whether the second identification information included in the input record information indicates the never copy or the one copy; a recording control device for determining on the basis of determinations of the first recording determination device and the second recording determination device whether recording the input record information onto the recording medium is permitted or prohibited; a recording device for recording the input record information onto the recording medium in accordance with a determination of the recording control device; an encryption control device for determining on the basis determinations of the first recording determination device and the second recording determination device whether or not the input record information is to be encrypted; and an encryption device for encrypting the input record information in accordance with a determination of the encryption control device.
The reproducing apparatus comprises: a read device for reading the record information from the recording medium; a first reproduction determination device for determining whether the first identification information included in the read record information indicates the never copy, the one copy or the copy free; a second reproduction determination device for determining whether or not the read record information is encrypted by the recording apparatus; an output control device for determining on the basis of determinations of the first reproduction determination device and the second reproduction determination device whether outputting the read record information is permitted or prohibited; an output device for outputting the read record information in accordance with a determination of the output control device; a decryption control device for determining on the basis of a determination of the second reproduction determination device whether or not the read record information is to be decrypted; a decryption device for decrypting the read record information in accordance with a determination of the decryption control device; a changing control device for determining on the basis of determinations of the first reproduction determination device and the second reproduction determination device whether or not the second identification information is to be changed such that the second identification information indicates the never copy; and a changing device for changing the second identification information such that the second identification information indicates the never copy, in accordance with a determination of the changing control device.
As stated above, the first identification information indicates any one of the never copy, the one copy and the copy free. To realize this first identification information having three statuses, for example, three different values may be used as the first identification information. Alternatively, only two different values may be used as the first identification information. In this case, the two values indicate the first status and the second status, and the absence of the value indicates the third status.
Furthermore, the second identical information is changed by the reproducing apparatus such that the second identical information indicates the never copy, when the reproducing apparatus reproduces the record information that is indicated as one copy and that has been recorded on the recording medium once. The first identification information is not changed by not only the reproducing apparatus but also the recording apparatus.
In the recording apparatus, the input device inputs the record information to the inside of the recording apparatus. The first recording determination device determines whether the first identification information included in the record information indicates the never copy, the one copy and the copy free. The second recording determination device determines whether the second identification information indicates the never copy or the one copy. On the basis of these two determinations, it can be determined that a copy restriction status of the record information is any one of the following four statuses.
(A) never copy
(B) one copy
(C) no more copy
(D) copy free
The xe2x80x9cno more copyxe2x80x9d means the prohibition of copying any more as the record information that is indicated as one copy has been recorded once onto the recording medium.
The recording control device determines on the basis of the copy restriction status (A), (B), (C) or (D) whether recording the record information onto the recording medium is permitted or prohibited. The recording device records the record information onto the recording medium, only when the recording control device determines that recording the record information is permitted.
Further, the encryption control device determines on the basis of the copy restriction status (A), (B), (C) or (D) whether the record information is to be encrypted or not. The encryption device encrypts the record information, only when the encryption control device determines that the record information is to be encrypted. In this case, the encrypted record information is recorded onto the recording medium.
Depending on the copy restriction status of the record information (A), (B), (C) or (D), the recording apparatus finally controls the recording of the record information as follows:
(i) When the copy restriction status of the record information is the never copy, the recording of the record information is prohibited. Therefore, the record information is not recorded onto the recording medium.
(ii) When the copy restriction status of the record information is the one copy, the record information is encrypted, and the recording of the record information is permitted. Therefore, the encrypted record information is recorded onto the recording medium.
(iii) When the copy restriction status of the record information is the no more copy, the recording of the record information is prohibited. Therefore, the record information is not recorded onto the recording medium.
(iv) When the copy restriction status of the record information is the copy free, the recording of the record information is permitted. Therefore, the record information is recorded onto the recording medium without being encrypted.
In the reproducing apparatus, the read device reads the record information from the recording medium. The first reproduction determination device determines whether the first identification information included in the record information indicates the never copy, the one copy and the copy free. The second reproduction determination device determines whether or not the record information has been encrypted by the recording apparatus. On the basis of these determinations, it can be determined that the copy restriction status of the record information is any one of the following four statuses.
(E) never copy
(F) no more copy
(G) copy free
(H) abnormal copy
xe2x80x9cAbnormal copyxe2x80x9d indicates, for example, that the record information was recorded onto the recording medium by an recording apparatus except for the recording apparatus of this system, or that the record information has been altered illegally or in a dishonest manner. For example, it is assumed that there is a case where the first identification information indicates the one copy, but the record information has not been encrypted. There is no possibility that such a case occurs as long as the record information was recorded on the recording apparatus of this system.
After the copy restriction status of the record information is determined, the output control device determines on the basis of the copy restriction status of the record information whether outputting the record information in permitted or prohibited. The output device outputs the record information to an external apparatus or a communication means, only when the output control device determines that outputting the record information is permitted.
Furthermore, the decryption control device determines on the basis of the copy restriction status of the record information whether the record information is to be decrypted or not. The decryption device decrypts the record information, only when the decryption control device determines that the record information is to be decrypted.
Depending on the copy restriction status of the record information (E), (F), (G) or (H), the reproducing apparatus finally controls the outputting of the record information as follows:
(i) When the copy restriction status of the record information is the never copy, the outputting of the record information is permitted. Therefore, the record information is output from the reproducing apparatus. If a digital monitor is connected with the reproducing apparatus, a user or an audience can watch the image or picture corresponding to the record information. If the recording apparatus of this system is connected with the reproducing apparatus, the record information cannot be copied to another recording medium, because the recording apparatus prohibits the recording of this record information.
(ii) When the copy restriction status of the record information is the no more copy, the record information is decrypted, and the outputting of the record information is permitted. Therefore, the decrypted record information is output from the reproducing apparatus. If a digital monitor is connected with the reproducing apparatus, a user or an audience can watch the image or picture corresponding to the record information. If the recording apparatus of this system is connected with the reproducing apparatus, the record information cannot be copied to another recording medium, because the recording apparatus prohibits the recording of this record information.
(iii) When the copy restriction status of the record information is the copy free, the outputting of the record information is permitted. Therefore, the record information is output from the reproducing apparatus. If a digital monitor is connected with the reproducing apparatus, a user or an audience can watch the image or picture corresponding to the record information.
(iv) When the copy restriction status of the record information is the abnormal copy, the outputting of the record information is prohibited. Therefore, the record information is not output from the reproducing apparatus. As a result, a user or an audience cannot watch the image or picture corresponding to the record information.
Further, in the reproducing apparatus, the changing control device determines on the basis of the copy restriction status of the record information whether or not the second identification information included in the record information is to be changed such that the second identification information indicates the never copy (or no more copy). The changing device changes the second identification information such that the second identification information indicates the never copy (or no more copy), only when the changing control device determines that the second identification information is to be changed.
Therefore, when the copy restriction status of the record information is the no more copy, the second identification information included in the record information is changed such that the second identification information indicates the never copy (or no more copy). Accordingly, if the recording apparatus of this system is connected with the reproducing apparatus, the record information cannot be copied to another recording medium any more.
Accordingly, by the system in accordance with the present invention, the copying of the record information can be sufficiently prevented.
In the above-stated system, the digital-analog converting device and an analog output device may be added to the reproducing apparatus. The digital-analog converting device converts the record information output by the output device into an analog signal. The analog output device outputs the analog signal to an external apparatus or an external communication means. Therefore, it is possible to prevent the record information from copying by way of an analog transmission. In this case, the changing control device may determines whether or not the second identification information is to be changed, only when the record information is to be output as the analog signal. Therefore, it is possible to simplify the changing process of the second identification information.
In the above-stated system, the output device outputs the record information as a digital signal to an external apparatus or the like. Further, in the above-stated system, an external apparatus determination device may be added to the reproducing apparatus. The external apparatus determination device determines whether or not the external apparatus is authorized. In this case, the output control device determines that outputting the read record information is prohibited, when the first reproduction determination device determines that the first identification information indicates never copy and the external apparatus determination device determines that the external apparatus is not authorized. And, the output control device determines that outputting the read record information is prohibited, when the first reproduction determination device determines that the first identification information indicates one copy and the external apparatus determination device determines that the external apparatus is not authorized.
If such an external apparatus determination device is added to the reproducing apparatus, the reproducing apparatus finally controls the digital output of the record information as follows, depending on the aforementioned copy restriction status of the record information (E), (F), (G) or (H), and a determination of the external apparatus detemination device:
(i) When the copy restriction status of the record information is the never copy, and the external apparatus is not authorized, the digital output of the record information is prohibited.
(ii) When the copy restriction status of the record information is the no more copy, and the external apparatus is not authorized, the digital output of the recording information is prohibited.
(iii) When the copy restriction status of the record information is the copy free, the digital output of the record information is permitted. In this case, the determination of whether the external apparatus is authorized may be disregarded.
(iv) When the copy restriction status of the record information is the abnormal copy, the digital output of the record information is prohibited regardless of whether the external apparatus is authorized or not.
Thus, if the external apparatus determination device is added to the reproducing apparatus, if a digital monitor is assigned to an authorized apparatus, and if a recording apparatus except for the recording apparatus of this system (i.e., a non-compliant recording apparatus) is not assigned to the authorized apparatus, a user or an audience can watch the image or the picture corresponding to the record information with the digital monitor, but cannot copy the record information to the another recording medium with the non-compliant recording apparatus. Accordingly, it is possible to prevent the record information from copying by way of a digital transmission.
In the above-stated system, the record information may further includes a third identification information which represents any one of the never copy, the one copy and the copy free. In this case, a third recording determination device is added to the recording apparatus. The third recording determination device determines whether the third identification information included in the input record information indicates the never copy, the one copy or the copy free. Furthermore, in this case, the recording control device determines on the basis of determinations of the first recording determination device, the second recording determination device and the third recording determination device whether recording the input record information onto the recording medium is permitted or prohibited. By adding such devices, the copying of the record information can be more sufficiently prevented.
In addition to this, a third reproduction determination device may added to the reproducing apparatus. The third reproduction determination device determines whether the third identification information included in the read record information indicates the never copy, the one copy or the copy free. In this case, the output control device determines on the basis of determinations of the first reproduction determination device, the second reproduction determination device and the third reproduction determination device whether outputting the read record information is permitted or prohibited. Therefore, the copying of the record information can be more sufficiently prevented.
Furthermore, a receiving apparatus may be added to the above-stated system. The receiving apparatus is an apparatus for receiving the record information transmitted from an information generation source and outputting the received record information to the recording apparatus.
The receiving apparatus comprises: an information output device for outputting the received record information to the recording apparatus as a digital signal; an information determination device for determining whether the first identification information included in the received record information indicates the never copy, the one copy or the copy free; a recording apparatus determination device for determining whether or not the recording apparatus is authorized; an information output control device for determining on the basis of determinations of the information determination device and the recording apparatus determination device whether outputting the received record information is permitted or prohibited.
The receiving apparatus can output the received record information to the recording apparatus as a digital signal. To restrict the copying of the record information, the information output control device determines that outputting the received record information is permitted, when the information determination device determines that the first identification information indicates one copy and the recording apparatus determination device determines that the recording apparatus is authorized. Only when the information output control device determines that outputting the received record information is permitted, the received recording information is supplied to the recording apparatus. This means that it can be prevented the copying of the record information at the entrance of the system.
Furthermore, the above-stated object can be also achieved by another types of system in accordance with another aspect of the present invention. This system comprises a recording apparatus for recording record information onto a recording medium as digital data and a reproducing apparatus for reading the record information from the recording medium and outputting the read record information to reproduce the record information recorded on the recording medium. The record information includes: image information which represents an image or a picture; a first identification information which represents any one of the never copy, the one copy and the copy free; and a second identification information which represents any one of at least the never copy and the one copy.
The recording apparatus comprises: an input device for inputting the record information; a first recording determination device for determining whether the first identification information included in the input record information indicates the never copy, the one copy or the copy free; a second recording determination device for determining whether the second identification information included in the input record information indicates the never copy or the one copy; a recording control device for determining on the basis of determinations of the first recording determination device and the second recording determination device whether recording the input record information onto the recording medium is permitted or prohibited; a recording device for recording the input record information onto the recording medium in accordance with a determination of the recording control device; an encryption control device for determining on the basis determinations of the first recording determination device and the second recording determination device whether or not the input record information is to be encrypted; an encryption device for encrypting the input record information in accordance with a determination of the encryption control device; and a certification information adding device for adding a certification information to the input record information, the certification information indicating that the input record information is recorded by the recording apparatus.
This recording apparatus has the same devices as the above-stated recording apparatus except for the certification information adding device.
The reproducing apparatus comprises: a read device for reading the record information from the recording medium; a first reproduction determination device for determining whether the first identification information included in the read record information indicates the never copy, the one copy or the copy free; a second reproduction determination device for determining whether or not the certification information is included in the read record information; an output control device for determining on the basis of determinations of the first reproduction determination device and the second reproduction determination device whether outputting the read record information is permitted or prohibited; an output device for outputting the read record information in accordance with a determination of the output control device; a decryption control device for determining on the basis of a determination of the second reproduction determination device whether or not the read record information is to be decrypted; a decryption device for decrypting the read record information in accordance with a determination of the decryption control device; a changing control device for determining on the basis of determinations of the first reproduction determination device and the second reproduction determination device whether or not the second identification information is to be changed such that the second identification information indicates the never copy; and a changing device for changing the second identification information such that the second identification information indicates the never copy, in accordance with a determination of the changing control device.
This reproducing apparatus has the same devices as the above-stated reproducing apparatus except for the second reproduction determination device.
In this system, the certification information is added to the record information, when the recording of the record information is carried out by the recording apparatus. In the reproducing apparatus, the second reproduction determination device determines whether or not the certification information is included in the record information, when the record information is reproduced. Then, the output control device determines on the basis of the first identification information and the certification information whether outputting the read record information is permitted or prohibited. Further, the decryption control device determines on the basis of the certification information whether or not the read record information is to be decrypted. Furthermore, the changing control device determines on the basis of the first identification information and the certification code whether or not the second identification information is to be changed.
According to such a system, the copying of the record information can be sufficiently prevented.
The nature, utility, and further feature of this invention will be more clearly apparent from the following detailed description with respect to preferred embodiments of the invention when read in conjunction with the accompanying drawings briefly described below.